This invention relates to a volume management module for data transfer between a plurality of devices connected to buses.
There are times when peer-to-peer data transfer (direct data transfer between a plurality of devices without using a main memory unit) is implemented to reduce load on the Central Processing Unit (CPU) and buses during data transfer. For peer-to-peer data transfer, however, data transfer could be disabled or efficiency of data transfer may be degraded on account of physical positions of the devices or the type of available buses. Some buses are fixed to a certain transfer source or destination device, disabling peer-to-peer transfer between arbitrary devices. Such buses are called a peer-to-peer transfer incapable bus.
Referring to FIG. 13, if a bus 1 is assumed to be a-peer-to-peer incapable bus, and buses 2a and 2b are peer-to-peer transfer capable buses, then data transfer between physical devices 60a and 61a and a device (Input/Output (I/O) processor) 5b, or between physical disks 60b and 61b and a device (I/O processor) 5a is disabled because of the peer-to-peer data transfer incapable path. If data is sent through such a transfer incapable path, a fatal failure may occur.
In a conventional peer-to-peer data transfer, the data transfer capability is decided only with a unit of devices physical disks). However, there is a volume management system that can configure a logical volume with a plurality of partitions in different physical disks. The term partition could cover all of the disks or part of them. The term logical volume refers to a single logical memory made up of two or more partitions combined. The term logical volume includes the all levels (0 through 5) of Redundant Arrays of Inexpensive Disk (RAID) and a spanned volume. Such a volume management system is not compatible with peer-to-peer data transfer because it is impossible to select a destination device (I/O processor, etc.) appropriate to a physical disk containing data. When a logical volume 7 is configured as shown in FIG. 13, the peer-to-peer transfer incapable path which disables data transfer to devices (I/O processor) 5a and 5b is included, whereby peer-to-peer data transfer between the logical volume and the I/O processor is disabled.
Suppose bus 1 is peer-to-peer transfer capable, and the paths from bus 2a and bus 2b to bus 1 are inefficient peer-to-peer transfer paths, and the transfer paths that take only bus 2a and only bus 2b are efficient peer-to-peer transfer paths. Then, if the logical volume 7 is configured, because there are paths by which transfer efficiency is low for both the devices (I/O processor) 5a and 5b, the advantage in peer-to-peer data transfer performance between the logical volume and the I/O processor would be lost.
With the conventional peer-to-peer data transfer, safe and highly efficient data transfer was impossible when a logical volume configured with a plurality of partitions in different physical disks is set as the source or destination of data transfer.
This invention aims to solve the above-mentioned problem. This invention aims at offering a data transfer apparatus between devices that controls peer-to-peer data transfer between the logical volume and destination device or between the logical volume and source device for the data transfer apparatus between devices having a volume management system that can configure the logical volume to include a plurality of partitions.
Moreover, this invention aims at offering a data transfer for data transfer between devices which does not send data to a path incapable of transfer or capable of only low transfer efficiency.
A data transfer apparatus for data transfer between devices, wherein a plurality of storage devices and a plurality of data processing devices are connected via a plurality of transfer paths, and a data is transferred between the storage devices and the data processing devices via at least one of the plurality of transfer paths may comprise a table for memorizing physical positions of the storage devices, physical positions of the plurality of data processing devices, and the data transfer efficiency of the plurality of transfer paths, and a data transfer control module for identifying whether data transfer is capable or not between the storage devices and the data processing devices based on the physical positions of the plurality of storage devices, the physical positions of the plurality of data processing devices, and the data transfer efficiency of the plurality of transfer paths memorized on the table.
The data transfer apparatus between devices, wherein the data transfer control module may issue warning against a selection of the transfer path with poor transfer efficiency.
The data transfer apparatus between devices may further comprise a main memory unit, and wherein the data transfer control module may transfer the data to the main memory unit without transferring the data between the devices if the transfer path with poor transfer efficiency is selected.
The data transfer apparatus between devices, wherein the table may memorize a capability/incapability of data transfer as the data transfer efficiency, and wherein the data transfer control module may classify the capability/incapability of data transfer based on the capability/incapability of data transfer.
The data transfer apparatus between devices may further comprise a volume management module which specifies a combination of storage devices to/from which the data can be transferred, based on the physical positions of the plurality of storage devices, the physical positions of the plurality of data processing devices, and the data transfer efficiency of the plurality of transfer paths.
The data transfer apparatus between devices, wherein the volume management module may automatically create a logical volume from the combination of the storage devices to/from which the data can be transferred.
The data transfer apparatus between devices, wherein the volume management module may prohibit a creation of the logical volume which includes a storage device not included in the combination of the storage devices to/from which the data can be transferred.
The data transfer apparatus between devices, wherein the data transfer control module may select the data processing device using the transfer path with high transfer efficiency, based on the physical positions of the plurality of storage devices and the physical positions of the plurality of data processing devices constituting the logical volume having redundancy, and the transfer efficiency of the plurality of transfer paths.
The data transfer apparatus between devices, wherein the data transfer control module may identify the capability/incapability of data transfer in a unit of files.
The data transfer apparatus between devices, wherein the data transfer control module may identify the capability/incapability of data transfer in the unit of data blocks.
The data transfer apparatus between devices, wherein the data transfer control module may select the data transfer device in the unit of files.
The data transfer apparatus between devices, wherein the data transfer control module may select the data transfer device in the unit of data blocks.
A data transfer apparatus between devices, wherein a plurality of storage devices and a plurality of data processing devices may be connected via a plurality of transfer paths, and a data may be transferred between the storage devices and the data processing devices via at least one of the plurality of the transfer paths may comprise a table for memorizing physical positions of the storage devices, physical positions of the plurality of data processing devices, data transfer efficiency of the plurality of transfer paths, and; a volume management module for identifying a combination of storage devices capable of data transfer, based on the physical positions of the plurality of storage devices, the physical positions of the plurality of data processing devices, and the data transfer efficiency of the plurality of transfer paths.
The data transfer apparatus between devices, wherein the volume management module may automatically create a logical volume from the combination of the storage devices to/from which the data can be transferred.
The data transfer apparatus between devices, wherein the volume management module may prohibit a creation of the logical volume including a storage device not included in the combination of the storage devices to/from which the data can be transferred.
The data transfer apparatus between devices, wherein the table may memorize the data transfer capability/incapability as the data transfer efficiency, and wherein the volume management module may identify the combination of the storage devices based on the capability/incapability of data transfer.
A data transfer method between devices, wherein a plurality of storage devices and a plurality of data processing devices may be connected via a plurality of transfer paths, and a data may be transferred between the storage devices and the data processing devices via at least one of the plurality of transfer paths may comprise the steps of memorizing physical positions of the storage devices, physical positions of the plurality of data processing devices, and data transfer efficiency of the plurality of transfer paths, and controlling data transfer for identifying the capability/incapability of data transfer between the storage devices and the data processing devices, based on the physical positions of the plurality of storage devices, the physical positions of the plurality of data processing devices and the data transfer efficiency of the plurality of transfer paths memorized on the table.
The data transfer method between devices may further comprise a step of managing a volume for identifying a combination of storage devices capable of data transfer, based on the physical positions of the plurality of storage devices, the physical positions of the plurality of data processing devices, and the data transfer efficiency of the plurality of transfer paths memorized on the table.